rajul

My Feedback: (58)

Hi Folks ! When I put a ply fuse together, I normally apply medium ca to the inner and outer seams, followed by thick ca to get a fillet. So far I had not faced any problems, but as I move towards bigger planes, I am concerned if the ca ply joints will turn out to be brittle. Any inputs on what is the best way to glue ply joints ?

Cleared4Crash

Well..."best" is a tricky word here in the forum. You could do what many have done before, make up some test joints with various methods on scrap pieces. Then try to break the joint using your method of choice. Not very scientific, but will give you a rough idea on joint strength.

TerrellFlyer

Morning rajul,on ply joints I haven't had much good luck with ca,I use epoxy or aliphatic glue with a little tacking in place with ca

FLYBOY

My Feedback: (11)

I use thick CA and put triangle stock in the corners. Never had a problem, even on the huge ones. Epoxy and triangle stock on the firewall, and where I cant get triangle stock in, I use a white glue fillet. Works great.

Elwood

My Feedback: (2)

Titebond II gets my vote. Wood glue.

Gene Chernosky

My Feedback: (182)

Titebond II is by FAR the BEST wood glue I have EVER used. I used to build cabinets for a living and this is the only wood glue I allow in my shop to this day...it's STRONG! Also, it's light when dry...and isn't brittle like CA's can sometimes be after a while. One must remember that just because something sets fast doesn't necessarily mean it is a "better" adhesive.

jettstarblue

Titebond II, Weldbond, or slow epoxy. Epoxy is heavy.

Jetts

IronCross

Titebond. I have read a couple of threads where test were done and Titebond made a stronger joint on hardwood then CA or Epoxy. Seems it soaks in and grabs better. I prefer the original Titebond though. I think it sands easier.

rajul

My Feedback: (58)

I am assemblying the fuse for my 4*60 now and I have not decided on how I want to glue it. The manual recommends to assemble the fuse pieces together and hold the entire assembly with rubberbands and glue the plywood-to-plywood butt joints with medium and thick ca. I was thinking of using titebond but I think if I were to apply it at the corners, it will not seep into the joint. It will be inconvenient to apply titebond at the end faces of the plywood and then assemble again. Also the clamping force by the rubberbands may not be enough and some gaps may be too large for titebond to be effective. What gluing method would you use for the fuse assembly of the 4*60 ? Thanks for your invaluable inputs.

Volfy

My Feedback: (23)

Rajul, I did the rubber band and CA thing as suggested in the manual. I then added tri-stock where ever I can along the lengthwise joints. Liteply to liteply butt joints just don't look like enough gluing surface to me. Adding tri-stock increase that tremendously, without adding a lot of weight.

What glue you should use is not as important as making sure all the glue joints are evenly tight. The rubberbands are just there to hold the whole assembly together. You need to use the old fingers to press the sides together tight when you hit it with CA. Do it one small section at a time. Check the fuselage straghtness as you go. If you use a slower drying glue, you'll have to use clamps.

rajul

My Feedback: (58)

Hi Volfy, did you use ca for the tristocks as well ? How's your WM superstunt and 4*60 coming along ?

Volfy

My Feedback: (23)

I cut the tristock to length, then "grab" it and set it in place with my hobby knife. I use Medium CA.

The 4*60 project as a whole is crawling along. Too many other projects and other distractions. I'm done with the basic fuselage, that's about it.

My SuperStunt 60 is back on the workbench. I wasn't too happy with its performance with the ASP 120 4stroke, so I'm replacing it with a TT 120RP on a tuned pipe.

rajul

My Feedback: (58)

Volfy, what do you mean by "grabbing" and setting with the knife ? Sorry for the "basic" question.

BALSA BANDIT

If you can clamp the wood and wait 24 hours, I don't know of anything better than "GORILLA GLUE". Once its cured, you can't break it and the mfgr. states that nothing n earth can make it come loose.

Rodney

In general, plywoods and most hardwoods are more acidic than normal balsa. CA does not do well in an acidic environment. The alphatic resin glues such a Titebond do a much better job. If you insist on using CA, you can help matters a bit with a light dusting of baking soda over the area you intend to glue. It takes very little soda.

FLYBOY

My Feedback: (11)

I have found that the dusting of baking soda makes the glue go off better, but I tend to see really weak joints. I don't recommend it any more. If you use CA, go over it afterwards and put a filet of titebond wood glue in all the joints to help with strength. I use a round ended dental tool to put it where I want it and it works well.

rajul

My Feedback: (58)

Hi flyboy, what is this tool ? Could you post a pic please ?

Volfy

My Feedback: (23)

Sorry for the late reply. What I do is this:

1. Place the tri-stock piece in the intended position by hand.
2. ***** the tri-stock with the hobby knife from the position you'll be reinserting it.
3. Extract the tri-stock with the hobby knife.
4. Coat the gluing surfaces with medium CA.
5. Reinsert the tri-stock with the hobby knife.
6. Now take a popsicle stick and push on the tri-stock to help glue it down.
7. Extract the hobby knife.

This may sound convoluted but if you understand it, it's very simple and quick to do. Most importantly, you never get CA anywhere near your fingers.

BTW, popsicle sticks or craft sticks are $1.99 for a Box of 1000 at Hobby Lobby. Biggest bargain I've ever seen. I use it to mix epoxy and a variety of construction throw away tasks.

rajul

My Feedback: (58)

Thanks Volfy. It's this little techniques that we develop along the way that makes building more convenient, effective and enjoyable.

Volfy

My Feedback: (23)

Rajul, here're some pics of the tri-stock.

Volfy

My Feedback: (23)

Heavier tri-stock at the high stress areas.

rajul

My Feedback: (58)

What can I say ? A picture is worth a thousand words, and I hope it will be worth a thousand dollars to ya Volfy !

FHHuber

For lite ply such as in the 4*40 and 4*60, I prefer the yellow glues.

I've had the CA wick through the center layer of lite ply and grab my fingers 10 inches from where I put the CA. If the CA is wicking that far... its not staying in the joint where you want it.

You really need to use something other than CA for laminating the fuselage doublers onto the sides... Paint the doubler with yellow glue,(Gorrilla Glue is fine here.) place the fuselage side on plastic, position the doubler, cover with plastic and put a stack of books on top. (use a FLAT building surface!) This may take longer than CA for prepping the fuselage sides... but you can build the wing while this dries.

I haven't found enough of an advantage to the polyurethane glue (when dealng with lite ply) to consider it worth the extra cost vs the yellow glue. The "Gorrilla Glue" and similar are good, and help to make a strong aircraft. There are places where I do use these glues.

For putting the firewall into the lite ply fuselage... EPOXY. I pant the joint with 2 hour epoxy, let it soak n for a couple of minnutes, then apnt the edges again before putting the pieces together.
Then I paint the firewall, inside the cheek cowls and in the fuel tank area for fuelproofing (not necesarilly the same batch for that...) 2 hour epoxy soaks in for the best fuelproofng and for the best bond. (I'm not buying 30 min at all any more, and 5 min is just for small repairs at the field.)

rajul

My Feedback: (58)

fhhuber, nice to see you here